Agent for use in the case of fructose intolerance

ABSTRACT

There is provided a method for treating or reducing the effects of fructose intolerance and health problems associated with excessive fructose intake by administration of glucose isomerase. Other embodiments are also disclosed.

This application is a continuation of U.S. Ser. No. 15/598371, filed May18, 2017, which is a continuation of U.S. Ser. No. 15/019977, filed Feb.10, 2016, which is a continuation of Ser. No. 13/833092, filed Mar. 15,2013, which is a continuation-in-part of U.S. Ser. No. 12/544242, filedAug., 20, 2009, which is a continuation-in-part of PCT/EP2008/001294,filed Feb. 20, 2008, which claims priority from DE 10 2007 008 664.6,filed Feb. 20, 2007. The priority and/or benefit of each of theseapplications, as appropriate, is claimed, and contents of theseapplications are incorporated herein by reference.

This patent application discloses an agent for use in the case offructose intolerance, which contains a compound that effects theconversion of fructose to glucose. The term fructose intolerance is usedin the context of this patent application to mean not only the medicallydefined fructose intolerance and fructose metabolism disorder (seebelow), but any form of impairment of health or well-being that occursas a result of the intake of fructose or fructose containing foodstuffs,or due to the release of fructose in the. digestive tract of humans oranimals from other substances, such as sucrose.

In the context of this patent application, the terms “food” and“foodstuff” are used as synonyms. They mean to also include feed in thesense of animal feed.

Fructose is a ketohexose and is an important energy providing ingredientof food. It is present in numerous foodstuffs, as a component of di- andoligosaccharides, and/or as free fructose. Food such as fruit and fruitjuices contains large amounts of fructose, but in particular alsosucrose, which is cleaved to fructose and glucose in the body. In thefollowing, the term ‘fructose containing’ is used to mean all substancesand foodstuffs that either contain fructose as such or in a form fromwhich fructose can be released in the digestive tract. The ‘fructosecontent’ of substances and foodstuffs refers to all the fructose in afructose containing food or substance in whatever form it is containedin such a food or substance (free and also e.g. as part of sucrose).

In contrast to glucose, fructose is assimilated into the mucosa cells ofthe small intestine by eased carrier-mediated diffusion. The enzymaticdegradation starts in the liver by the action of the adenosinetriphosphate (ATP) dependent fructo-kinase, whereby fructose isconverted to fructose-1-phosphate. In the liver and in the kidneys,fructose-1-phosphate is cleaved to glycerine aldehyde anddihydroxyacetone phosphate by aldolase B.

Three different types of fructose metabolism disorder are known inhumans, namely hereditary fructose intolerance, intestinal fructoseintolerance (sometimes also referred to as fructose non-absorption orfructose-malabsorption), and fructose-1,6-diphosphatase deficiency. Inaddition, there is fructosuria, which generally does not requiretreatment according to current scientific thinking

Hereditary fructose intolerance (HFI) results from a deficiency ofaldolase B, an enzyme that is present in the intestinal mucosa, theliver, lymphocytes and the kidneys. This enzyme usually breaks downfructose-1-phosphate to fructose-1,6-biphosphate via intermediatestages. If an aldolase B deficiency is present, an excess offructose-1-phosphate occurs, leading to an inhibition of glycogenbreakdown and of gluconeogenesis and, in turn, to severe hypoglycemiawith outbreaks of sweating, tremor, vomiting and cramps after the intakeof fructose. Acidosis, kidney damage and aminoaciduria can occur if thisremains undetected. In infants, the risk ranges from hemorrhages tosudden infant death syndrome.

The symptoms of the widespread intestinal fructose intolerance aredifferent, and its incidence is showing an increasing trend, especiallyin the western industrialized nations. It is caused by a disorder offructose absorption resulting from the impairment of transport processesin the mucosa of the small intestine. Those affected suffer from unclearabdominal symptoms and, as a result of the bacterial breakdown of thecarbohydrates passing into the colon, the production of intestinal gasesis increased. The symptoms include, e.g. a feeling of bloating,flatulence, colic-like stomachache, watery diarrhea, and bowel sounds.This is often incorrectly diagnosed as irritable colon.

Fructose-1,6-diphosphatase deficiency involves a deficiency of this keyenzyme in gluconeogenesis. This causes an increase in lactate levels inthe blood after fructose exposure and fasting hypoglycemia, withlactacidosis, seizures, muscular hypotension, and coma. The developmentof fatty liver also leads to hepatomegaly.

Not all disorders of fructose metabolism necessarily lead to severefructose in-tolerance. However, even in mild disorders of fructosemetabolism, health impairments are often to be observed, which hithertocould only be influenced by a change of diet. Excessive consumption offructose containing foodstuffs can also lead to health impairments.

The above-mentioned symptoms and complaints could only be avoided up tonow by maintaining a fructose-, sucrose- and sorbitol-free diet.However, it is very difficult for those affected to keep to such a diet,since fructose is contained in all fruits and many vegetables, and iswidely used as a sweetener by the foodstuffs industry. All foods thatcontain, e.g. sucrose (household sugar) also have to be avoided. Such adiet, which is indeed very strict in the case of hereditary fructoseintolerance, is not only difficult to keep to, it is also extremelyunfavorable from a nutritional physiological point of view, andconsiderably impairs the quality of life of those affected. Not onlythose affected, but also the specialist community, consisting ofdoctors, specialists, nutritional scientists, nutritional advisers,specialist journalists, etc., have assumed for decades that there is noalternative to maintaining the diet described above. Research focused onan alternative to this diet has remained unsuccessful to date. An agentthat would make it possible to do without maintaining such a diet andwould allow the intake of fructose containing food would thus satisfy anurgent need for the many people affected that has existed for decades.It would overcome a prejudice that has been established in thespecialist world and among those affected and mean a very considerableimprovement and a dramatic step forward in the therapeutic andnutritional options in fructose intolerance, since, apart frommaintaining a diet, there has simply been no therapy available up tonow. Such an agent would also put an end to the as yet unsuccessfulefforts of the specialist world to enable those affected to eat normallyand to consume fructose containing meals without suffering side effects.All of this would apply all the more to an agent that additionally hadno negative effects on health.

There is thus provided, in accordance with an embodiment of theinvention, a method of treating or reducing the effects in a subject ofa condition selected from fructose intolerance and impaired fructosemetabolism, the method comprising administering to a subject in need ofsuch treatment or reduction an efficacious amount of a glucoseisomerase, other than in combination with 5-D-fructose dehydrogenase. Insome embodiments, the condition is intestinal fructose intolerance. Insome embodiments, the glucose isomerase is administered prior to saidsubject's eating, concurrently with the subject's eating or after thesubject's eating. In some embodiments, the glucose isomerase isadministered within 15 minutes of the subject's eating. In someembodiments, the glucose isomerase is administered within 10 minutes ofthe subject's eating. In some embodiments, the glucose isomerase isadministered within 5 minutes of the subject's eating. In someembodiments, the glucose isomerase is administered with a second enzymewhich cleaves fructose from a sugar that is more complex than fructose.In some embodiments, the second enzyme is selected from the groupconsisting of invertase, maltase and combinations thereof. In someembodiments, the administration comprises oral administration.

There is also provided, in accordance with an embodiment of theinvention, a mammalian ingestible composition of matter selected from apharmaceutical composition and a dietary supplement, said composition ofmatter comprising a glucose isomerase, a second enzyme other than5-D-fructose dehydrogenase, and a carrier or excipient that isacceptable for use in pharmaceutical compositions, dietary supplementsor foodstuffs. In some embodiments, the composition of matter is in unitdosage form. In some embodiments, the composition of matter is in anorally administrable form. In some embodiments, the composition ofmatter is in a form selected from (a) the group consisting of a tablet,capsule, gel cap, pellet, granules and dragee, (b) the group consistingof a solution, a suspension and a gel, optionally which is a containedin a single-dose container and (c) powder form which is contained in asingle-dose container. In some embodiments, the composition of matter iscontained in a device operable to deliver a single dose or single dosesof the composition, such as a syringe for use with children adapted todeliver a single dose orally. In some embodiments, the glucose isomeraseis protected by a coating which is stable at pH below 4. In someembodiments, the glucose isomerase is protected by a coating whichdissolves at a pH of 5.5 or higher. In some embodiments, the compositionof matter is in unit dosage form and the coating protects the entiredosage unit. In some embodiments, the glucose isomerase ismicroencapsulated. In some embodiments, the glucose isomeraseconstitutes between 5 and 99.9% by weight of the composition of matter.In some embodiments, the unit dosage form contains between 0.01 and100,000 units of glucose isomerase activity. In some embodiments, thecomposition of matter comprises a coating which is stable at a pH below4. In some embodiments, the composition of matter comprises a coatingwhich dissolves at a pH of 5.5 or higher. In some embodiments, theglucose isomerase is not contained in an inorganic-based sol-gelbiocompatible matrix. In the context of this patent application, theterm “inorganic-based sol-gel biocompatible matrix” includes asilica-based sol-gel biocompatible matrix. In some embodiments, thesecond enzyme is selected from the group consisting of invertase,maltase and combinations thereof.

There is also provided, in accordance with embodiments of the invention,a foodstuff which comprises glucose isomerase, at least some of theglucose isomerase being present in the foodstuff in a form in which theglucose isomerase will be available in active form after ingestion ofthe foodstuff; a second enzyme other than 5-D-fructose dehydrogenase, atleast some of said second enzyme being present in said foodstuff in aform in which said second enzyme will be available in active form afteringestion of said foodstuff; and wherein, to the extent the foodstuffcontains 5-fructose dehydrogenase, the 5-fructose dehydrogenase will notbe available to act on fructose which is present in or released from thefood pulp in the digestive tract after ingestion of the foodstuff. Inthis manner, the glucose isomerase and, when present, the second enzymewill be available to act on their respective substrates which arepresent in or released from the food pulp present in the digestivetract. “Food pulp” in the context of this patent application constitutesany food, including that ingested before, concomitantly with or afterthe ingestion of the glucose isomerase-containing foodstuff, as well asthe glucose isomerase-containing foodstuff itself, that the activeglucose isomerase and, when present, active second enzyme encounter inthe digestive tract. In some embodiments, the foodstuff is selected fromthe group consisting of a cooked foodstuff, and a liquid foodstuff. Insome embodiments, the glucose isomerase is not contained in aninorganic-based sol-gel biocompatible matrix. In some embodiments, theglucose isomerase is microencapsulated. In some embodiments, thefoodstuff is substantially free of substances which are not approved fororal human ingestion. In some embodiments, the foodstuff is not a doughor a dough premix. In some embodiments, the foodstuff is not a bakedfoodstuff. In some embodiments, the foodstuff is not a bread.

There is also provided, in accordance with an embodiment of theinvention, a process for preparing a glucose isomerase-containingfoodstuff, the process comprising adding to a foodstuff glucoseisomerase in a form in which at least some of the glucose isomerase willbe available in active form after the foodstuff is ingested by asubject, whereby to obtain the glucose isomerase-containing foodstuff.In this manner, the glucose isomerase will be available to act onfructose which is present in or released from the food pulp present inthe digestive tract.

There is also provided, in accordance with an embodiment of theinvention, a kit comprising glucose isomerase and instructionsexplaining how to use the glucose isomerase to diagnose, treat, orreduce the effects of a condition selected from fructose intolerance andimpaired fructose metabolism. In some embodiments the condition isintestinal fructose intolerance (sometimes also referred to as fructosenon-absorption or fructose-malabsorbtion. In some embodiments theinstructions instruct to administer the glucose isomerase prior to thesubject's eating, concurrently with the subject's eating or after thesubject's eating. In some embodiments, the glucose isomerase isadministered within 15 minutes of the subject's eating. In someembodiments, the glucose isomerase is administered within 10 minutes ofthe subject's eating. In some embodiments, the glucose isomerase isadministered within 5 minutes of the subject's eating. In someembodiments the instructions instruct to administer the glucoseisomerase with a second enzyme which cleaves fructose from a sugar thatis more complex than fructose. In some embodiments the second enzyme isselected from the group consisting of invertase, maltase andcombinations thereof. In some embodiments the instructions instruct oraladministration. In some embodiments the instructions instruct toadminister the glucose isomerase other than in combination with a5-D-fructose dehydrogenase.

There is also provided, in accordance with an embodiment of theinvention, a foodstuff which comprises glucose isomerase, wherein saidfoodstuff is not a dough or a dough premix. In some embodiments, thefoodstuff is in unit dosage form. In some embodiments, the foodstuff isin a form selected from (a) the group consisting of a tablet, capsule,gel cap, pellet and dragee, (b) the group consisting of a solution, asuspension and a gel, optionally which is contained in a single-dosecontainer, or (c) powder which is contained in a single-dose container.In some embodiments, the composition of matter is contained in a deviceoperable to deliver a single dose or single doses of the composition,such as a syringe for use with children adapted to deliver a single doseorally. In some embodiments, the foodstuff is not a baked foodstuff. Insome embodiments, the foodstuff is not a bread. In some embodiments, atleast some of the glucose isomerase is present in the foodstuff in aform in which the glucose isomerase will be available in active formafter ingestion of the foodstuff. In this manner, the glucose isomerasewill be available to act on fructose which is present in or releasedfrom the food pulp present in the digestive tract. In some embodiments,to the extent the foodstuff contains 5-fructose dehydrogenase, the5-fructose dehydrogenase will not be available to act on fructose whichis present in or released from the food pulp present in the digestivetract after ingestion of the foodstuff. In some embodiments, thefoodstuff is selected from the group consisting of a cooked foodstuff,and a liquid foodstuff. In some embodiments, the glucose isomerase isnot contained in an inorganic-based sol-gel biocompatible matrix. Insome embodiments, the glucose isomerase is microencapsulated. In someembodiments, the foodstuff is substantially free of substances which arenot approved for oral human ingestion. In some embodiments, thefoodstuff contains a second enzyme other than 5-D-fructosedehydrogenase, at least some of said second enzyme being present in saidfoodstuff in a form in which said second enzyme will be available inactive form after ingestion of said foodstuff. In some embodiments, thefoodstuff is labeled as being advantageous for persons who suffer fromfructose intolerance and/or a fructose metabolism disorder.

In some embodiments, the glucose isomerase is isolated from a naturalsource. In some embodiments, the glucose isomerase is isolated from arecombinant source.

In some embodiments, the foodstuff further comprises a second enzymewhich is selected from the group consisting of invertase, maltase andcombinations thereof.

There are provided, in some embodiments of the present invention, aneffective agent that can be used not only in milder disorders offructose metabolism, but also in hereditary and intestinal fructoseintolerance and in fructose-1,6-diphosphatase deficiency, especially inorder to enable the consumption of normally fructose containingfoodstuffs even if fructose intolerance is present. Some embodiments ofthe invention make it possible for those affected by fructoseintolerance to eat foodstuffs that they were not allowed to eat up tonow, due to their fructose content. Some embodiments provide an agentthat can reduce or prevent the occurrence of fructose intolerancesymptoms after the intake of fructose.

In some embodiments, there is provided an agent that contains glucoseisomerase, other than in combination with 5-fructose dehydrogenase.

In this patent application, a glucose isomerase is an enzyme that isable to convert fructose into glucose. This conversion can also beachieved by a xylose isomerase. Thus, in the context of this patentapplication, a xylose isomerase is also a glucose isomerase. A possiblemethod for producing a xylose isomerase is described in Yamanaka,Biochimica et Biophysika Acta, issue 151 (3), 1968, 670-680,“Purification, Crystallization and Properties of the D-Xylose-Isomerasefrom Lactobacillus brevis” and in Yamanaka, Methods in Enzymology, issue41, 1971, 466-471, “D-Xylose Isomerase from Lactobacillus brevis”; thesedocuments are hereby incorporated by reference.

The agent according to embodiments of the present invention can bringabout the conversion of the fructose in food or in food pulp intoglucose. The fructose so converted is thus no longer available for thebacterial metabolism in the intestines characterized by fermentation,and the likelihood of an excess of fructose-1-phosphate occurring in theliver or elsewhere is reduced. This can also prevent an increase inlactate levels in the blood.

There is provided in accordance with some embodiments an agent thatreduces the bioavailability of fructose in the human or animal body withthe help of glucose isomerase.

There is also provided in accordance with some embodiments an agentthat, with the help of glucose isomerase, reduces the amount of fructoseavailable to the human or animal body or to intestinal bacteriacolonizing therein.

There is also provided in accordance with some embodiments an agent foruse in the case of fructose intolerance, which contains glucoseisomerase.

There is also provided in accordance with some embodiments the use ofglucose isomerase in the case of fructose intolerance.

There is also provided in accordance with some embodiments the use ofglucose isomerase for the production of a product for the use in thecase of fructose intolerance.

Glucose isomerase, which belongs to the group of isomerases, is anenzyme that has the property of converting D-fructose into D-glucose andvice versa. Here, an equilibrium of approximately 50% glucose and 50%fructose is established, depending on ambient temperature. Whereasfructose is only absorbed slowly from the small intestine, glucose is asugar that is easily digested and rapidly absorbed.

Thus, without wishing to be bound by theory, it is believed that someembodiments of the invention take advantage of the phenomenon ofingested fructose being converted into glucose in vivo by glucoseisomerase that is consumed simultaneously or at least shortly before orthereafter. The glucose isomerase then attempts to achieve theabove-mentioned equilibrium by converting fructose to glucose. However,glucose is absorbed very rapidly, so that the equilibrium cannot beachieved. Theoretically, the glucose isomerase may continue to convertfructose still available in the food pulp into glucose until no furtherfructose is left. The dose of glucose isomerase may be selected in sucha way that, even if larger amounts of fructose are consumed, thereaction can take place quickly enough that substantially no fructose isabsorbed or that the amount of fructose absorbed in the meantime is toosmall to cause the known gastrointestinal complaints in the case of mildfructose metabolism disorders and intestinal fructose intolerance andthe known systemic complaints in the case of hereditary fructoseintolerance and fructose-1,6-diphosphate deficiency.

As disclosed in co-pending application Ser. No. 12/093,822, the enzyme5-D-fructose dehydrogenase (syn. fructose 5-dehydrogenase) can bringabout the conversion of the fructose in food to 5-keto-D-fructose bydehydrogenation. Thus, the fructose is changed in such a manner that itis no longer available to the metabolism of the human or animal body. A5-D-fructose dehydrogenase in this sense is an enzyme that can bringabout the dehydrogenation of fructose to 5-keto-D-fructose. Particularlyfavorable effects can therefore be achieved if glucose isomerase and5-D-fructose dehydrogenase are used in combination. A possible methodfor the production of a 5-D-fructose dehydrogenase is, for example,described in Ameyama et al., Journal of Bacteriology 1981 , 814-823,“D-Fructose Dehydrogenase of Gluconobacter industrius: Purification,Characterization and Application of Enzymatic Microdetermination ofD-Fructose”, the content of which is incorporated herein by reference.

Thus, disclosed in co-pending application Ser. No. 12/093,822 is anagent that, beside glucose isomerase, additionally contains 5-D-fructosedehydrogenase. Such a combination agent can also be used in the form oftwo separate dose units, e.g. two separate tablets, one of whichcontains glucose isomerase and the other 5-D-fructose dehydrogenase.

In accordance with embodiments of the present invention, a glucoseisomerase can be used to reduce the fructose content in a foodstuff. Asdisclosed in co-pending application Ser. No. 12/093,822, a glucoseisomerase can be used in combination with 5-D-fructose dehydrogenase toreduce the fructose content of a foodstuff.

Foodstuffs in the sense of the present application also comprise, amongother things, foodstuffs for particular nutritional uses, foods forspecial medical purposes, medical foods, food supplements, dietarysupplements, dietetic food supplements, health foods, nutraceuticals,and food additives.

In some embodiments, the foodstuff may be labeled as being advantageousfor persons who suffer from fructose intolerance and/or a fructosemetabolism disorder. Such labeling (or, for that matter, any advertisingmaterial such as a product website) need not necessarily use the exactwords “advantageous for persons who suffer from fructose intoleranceand/or a fructose metabolism disorder”; the labeling (or advertisingmaterial such as a product website) may have words to similar effect.For example, the labeling (or advertising material such as a productwebsite) may state that the foodstuff is suitable for sufferers offructose intolerance (and may name the type of fructose intolerance); orthat the foodstuff is low in fructose content or has a reduced fructosecontent, or is low in effective fructose content, i.e. the amount offructose present as free fructose and fructose which can be cleaved fromother molecules; or that the foodstuff contains glucose isomerase (andmay indicate that the glucose isomerase is in active form); or that thefoodstuff contains enzyme(s) that reduce the fructose content (and mayindicate that the enzyme(s) lower the fructose content after consumptionof the foodstuff); or the labeling may be a symbol of approval from anorganization for fructose intolerance sufferers; or the labeling mayprovide instructions for use of the foodstuff as part of a regimen fortreating fructose intolerance or mitigating the effects or symptoms offructose intolerance; and the like. While it is contemplated that, ingeneral, it is the packaging in which the foodstuff is packaged thatwill bear the labeling, it will be appreciated that this need not be thecase, and that, for example, the foodstuff itself may bear suchlabeling, or that the foodstuff may be displayed in a place where suchlabeling is also displayed, even if not on the packaging. The labelingneed not necessarily use the exact words “for treatment of fructoseintolerance”. The labeling or advertising material such as a productwebsite may have words to similar effect, such as “for conversion offructose to glucose” or “for conversion of excess fructose to glucose”or “for conversion of fructose to glucose in the small intestine”.Furthermore, there is provided in accordance with an embodiment of theinvention a method for inducing a person to use glucose isomerase toconvert fructose to glucose in vivo, comprising providing a productcontaining glucose isomerase, advertising or causing to be advertised(for example on a web site, in an internet forum, or on a printedmedium) that the glucose isomerase may be used to convert fructose toglucose, and supplying the product to the person. In some embodimentsthe product is supplied directly to the person, for example via orderingfrom a web site. In some embodiments the product is supplied indirectlyto the person, for example via a wholesaler, a retailer or other thirdparty.

Embodiments of the present invention facilitate the transformation offructose in a foodstuff into a form that avoids the problems thataccompany fructose intolerance. Thus, embodiments of the presentinvention also make it possible for people affected by fructoseintolerance to consume such foodstuffs, which had to be avoided up tonow because of their fructose content.

In accordance with embodiments of the present invention, glucoseisomerase is further mentioned for use in medicine, for example as apharmaceutical composition. Accordingly, in accordance with embodimentsof the invention there is provided a product which contains or consistsof glucose isomerase along with one or more other active ingredients,for use in a medical method, in particular in a method for thetherapeutic treatment of the human or animal body. In this patentapplication, a pharmaceutical composition is a product, in particular asubstance or a substance mixture, for use in a method for surgical ortherapeutic treatment of the human or animal body or in diagnosticmethods that are performed on the human or animal body. Thus, in thisapplication, pharmaceutical compositions are also products, inparticular substances or substance mixtures, that are intended orsuitable for curing, alleviating, preventing or determining fructoseintolerance.

In accordance with embodiments of the present invention, a foodstuff isprovided which contains glucose isomerase in a form in which at leastsome of the glucose isomerase will exert its activity after ingestion ofthe foodstuff. In accordance with some embodiments, a foodstuff isprovided that contains glucose isomerase in an amount which issufficient to convert fructose into glucose after ingestion of thefoodstuff. In some embodiments, such a foodstuff may be produced using amethod for treating a foodstuff in which the foodstuff is placed incontact with a glucose isomerase under such conditions under which theglucose isomerase can convert fructose to glucose, provide that at leastsome of the glucose isomerase is incorporated into the foodstuff in amatter that it will exert activity after ingestion of the foodstuff. Incontrast to otherwise untreated foodstuffs, such a foodstuff willeffectively have a reduced fructose content after ingestion, and mayhave a reduced fructose content before ingestion as well, and thereforeis suitable to be consumed by persons suffering from fructoseintolerance. Thus in some embodiments, a foodstuff can be prepared by amethod in which a glucose isomerase is added to the foodstuff in amanner in which the action of at least some of the glucose isomeraseonly starts after the intake of the foodstuff. Such a foodstuff thatcontains glucose isomerase has the same taste as an untreated foodstuffand is suitable to be consumed by persons suffering from fructoseintolerance, due to the reduced fructose content which is establishedafter eating.

In some embodiments, a medical device is provided that contains glucoseisomerase. Thus in accordance with some embodiments there is provided amedical device which consists of a glucose isomerase or contains aglucose isomerase along with one or more other active ingredients. Inthis application a “medical device” means any instrument, apparatus,appliance, material or other article, whether used alone or incombination, including the software necessary for its proper applicationintended by the manufacturer to be used for human beings for the purposeof:

-   -   diagnosis, prevention, monitoring, treatment or alleviation of        disease,    -   diagnosis, monitoring, treatment, alleviation of or compensation        for an injury or handicap,    -   investigation, replacement or modification of the anatomy or of        a physiological process,    -   control of conception,        and which does not achieve its principal intended action in or        on the human body by pharmacological, immunological or metabolic        means, but which may be assisted in its function by such means:

Any instrument, apparatus, appliance, material or other article thatdoes not achieve its intended action in or on the human body is not amedical device in the context of this patent application.

In the following, embodiments of the invention will be described furtherin various aspects. If the term agent is used below, this also standsfor a foodstuff, a medical device or a pharmaceutical composition.

Glucose isomerase is a compound that has been known for more than 40years and has only been used for starch saccharification to date. In theindustry, it is used for the conversion of glucose into fructose as wellas for the conversion of fructose into glucose.

The agents in accordance with embodiments of the present invention canbe taken orally before meals, with meals or immediately after meals, sothat they can exert their converting effect on fructose in the foodpulp. Preferably, the agents are taken just before meals, during mealsor immediately after meals. The agents may contain the enzyme withoutfurther additives. However, in some embodiments the agents furthercontain additives that are pharmaceutically acceptable and/or acceptablefor foodstuffs, such as extenders, binders, stabilizers, preservatives,flavorings, etc. Such additives are commonly used and well known for theproduction of pharmaceutical compositions, medical devices, foodstuffs,foodstuffs for particular nutritional uses, foods for special medicalpurposes, medical foods, food supplements, dietary supplements, dieteticfood supplements, health foods, nutraceuticals, and food additives andspecialists in this field know which additives in which amounts aresuitable for particular presentation forms. In some embodiments, theagents contain as additives dicalcium phosphate, lactose, modifiedstarch, microcrystalline cellulose, maltodextrin and/or fibersol.

In accordance with some embodiments, the agents can be added to afoodstuff before eating. They can even be added to the foodstuff at theproduction stage, with the aim of developing their effect only afterconsuming the foodstuff. This could possibly be achieved bymicroencapsulation, for example. In this way, the useable fructosecontent of the foodstuff would be reduced in a particularly advantageousway, without negatively affecting its taste. Therefore, in someembodiments of the invention there are provided preparations containingglucose isomerase that do not release at least some of this enzyme untilit reaches the digestive tract of a human or animal, or let the enzymebecome active in another way, especially in the stomach or smallintestine. Therefore, in accordance with embodiments of the invention,glucose isomerase could be used for example in the production of sweets,fruit preparations (e.g. apple sauce), jam, honey, chocolate andchocolate products, bakery products (e.g. biscuits and cakes), breads,pastas, vegetable dishes, potato dishes, ice cream, cereals, dairyproducts (e.g. fruit yogurt and pudding), fructose containing beverages,fructose containing sauces (e.g. tomato ketchup) and fructose containingsweeteners. For dishes that are boiled or baked, the agents could, e.g.be mixed into or sprinkled onto them after cooling.

Since fructose is widely used as a sweetener in foodstuffs that areespecially produced for diabetics, the addition of the agents inaccordance with embodiments of the present invention to diabetic foodbefore eating or the addition of the agents during the production ofdiabetic food is especially advantageous, to allow diabetics who sufferfrom fructose intolerance to eat diabetic food, such as the abovementioned foodstuffs in their respective form as diabetic foods.

The agents can also be added to a foodstuff to exert their effect onfructose originating from a different foodstuff. An example of thiswould be the addition of the agents to a spread so that the reduction ofthe utilizable fructose contained in the bread upon which the spread isspread occurs after ingestion of the bread, without impairing the tasteof the bread. Another example would be mixed spices.

In some embodiments, the agents also contain other active ingredients.

For use in accordance with embodiments of the invention, the glucoseisomerase may be formulated in any form which is suitable for theintended route of administration. For oral administration, the agentsmay be formulated in the form of capsules (coated or non-coated),tablets (coated or non-coated), capsules containing coated or non-coatedpellets, granules, or micro- or mini-tablets, tablets pressed fromcoated or non-coated pellets, dragees, or micro- or mini-tablets, gelcaps or, in liquid form, as a solution, drops, suspension or gel. Theformulation of the agent in accordance with embodiments of the presentinvention as a powder is particularly suitable for an admixture to afoodstuff. The powder may be sprinkled onto a meal or it may be mixedinto a pulp or a beverage. It is particularly suitable if the agentoffered as bulk powder is packed in single dosage amounts, such as insingle bags or capsules, or if it is provided in a dosing apparatus. Itis especially preferable if the agent is formulated as a powder or asgranules in capsules or as a tablet that are administered orally.

For oral administration, the glucose isomerase may be mixed withacceptable excipients and/or carriers. The term “acceptable carrier”relates to either a carrier for pharmaceutical use or for use in afoodstuff such as a dietary supplement which directs the activeingredient to its target site and which does not have negative effectsfor the recipient, human or animal. However, the exact form of thecarrier is not decisive.

The total amount of the carrier and/or excipients of an agent containingglucose isomerase is preferably between 5 and 99.9% by weight, morepreferably between 10 and 95% by weight and even more preferably between25 and 90% by weight of the composition.

Suitable excipients and/or carriers include maltodextrin, calciumcarbonate, dicalcium phosphate, tricalcium phosphate, microcrystallinecellulose, dextrose, rice flour, magnesium stearate, stearic acid,croscarmellose sodium, sodium starch glycolate, crospovidone, sucrose,vegetable gums, lactose, methylcellulose, povidone, carboxymethylcellulose, corn starch, modified starch, fibersol, gelatine,hydroxypropylmethyl cellulose and the like (including mixtures thereof).Preferable carriers include calcium carbonate, magnesium stearate,maltodextrin, dicalcium phosphate, modified starch, microcrystallinecellulose, fibersol. gelatine, hydroxypropylmethyl cellulose andmixtures thereof.

The various ingredients and the excipient and/or carrier are mixed andformed into the desired form using common methods. The presentation formwhich is intended for oral administration, such as a tablet or capsule,may be coated with a coating that is resistant to low pH values. Thismakes it possible for the enzyme to be released only when they reach thesmall intestine. Also a coating may be used which is not resistantagainst low pH values but which provides delayed release of therespective enzyme at low pH values. It is also possible to prepare theagent in accordance with embodiments of the present invention as coated(see above) pellets, granules, or micro- or mini-tablets which can befilled into non-coated capsules or which can be pressed into non-coatedtablets. Suitable coatings are, for example, cellulose acetatephthalate, cellulose derivatives, shellac, polyvinylpyrrolidonederivatives, acrylic acid, polyacrylic acid derivatives and polymethylmethacrylate (PMMA), such as Eudragit® (from Röhm GmbH, Darmstadt), e.g.Eudragit® FS30D (releases the active constituent or constituentsstarting at a pH of around 6.8) and/or Eudragit® L30D-55 (releases theactive constituent or constituents starting at a pH of around 5.5). Ifit is desired to release the enzyme(s) already at a lower pH value, thismay be achieved e.g. by the addition of sodium hydroxide solution to thecoating agent Eudragit® L30D-55, because in this case carboxyl groups ofthe methacrylate would be neutralised. Therefore, this coating will bedissolved, for example, already at a pH value of 4.0 provided that 5% ofthe carboxyl groups are neutralised. The addition of about 100 g of 4%sodium hydroxide solution to 1 kg of Eudragit® L30D-55 would result in aneutralisation of about 6% of the carboxyl groups. Further details aboutformulation methods and administration methods can be found in the 21stedition of “Remington: The Science & Practice of Pharmacy”, published2005 by Lippincott, Williams & Wilkins, Baltimore, USA, in theEncyclopedia of Pharmaceutical Technology (Editor James Swarbrick) andin Prof. Bauer “Lehrbuch der Pharmazeutischen Technologie”, 18thedition, published 2006 by Wissenschaftliche Verlagsgesellschaft (ISBN3804-72222-9). The contents of these documents are incorporated hereinby reference.

Other suitable pharmaceutically or dietarily acceptable carriers orexcipients include water, mineral oil, ethylene glycol, propyleneglycol, lanolin, glyceryl stearate, sorbitan stearate, isopropylmyristate, isopropyl palmitate, acetone, glycerine, phosphatidylcholine,sodium cholate and ethanol, but are not limited thereto.

The compositions for use in accordance with embodiments of the presentinvention may also comprise at least one coemulsifying compound, such asoxyethylenated sorbitan monostearate, fatty alcohols such as stearylalcohol or cetyl alcohol, or esters of fatty acids and polyols, such asglyceryl stearate, but not limited thereto.

Preferably, the agents to be used in accordance with embodiments of thepresent invention are provided in a stabilized form. Generally,stabilization methods and procedures which may be used include any andall methods for the stabilization of chemical or biological materialwhich are known in the art, comprising e.g. the addition of chemicalagents, methods which are based on temperature modulation; methods whichare based on irradiation or combinations thereof. Chemical agents thatmay be used according to the present invention include, among others,preservatives, acids, bases, salts, antioxidants, viscosity enhancers,emulsifying agents, gelatinizers, and mixtures thereof.

Conventionally, the industrial production of enzymes is performed in atechnical fermentation way using suitable microorganisms (bacteria,moulds, yeasts). The strains are recovered from natural ecosystemsaccording to a special screening protocol, isolated as pure cultures aswell as improved in their properties with respect to the enzyme spectrumand biosynthesis performance (volume/time yield). The enzymes can alsobe produced using methods to be developed in the future.

Glucose isomerase is commercially available (e.g. Novozymes A/S, Denmarkand Danisco, Denmark) and is usually prepared in a microbiological waywith the help of the microorganism Streptomyces murinus. However,practice of embodiments of the invention is not limited to utilizingenzymes that are commercially available at the moment, but generallyrelates to enzymes that can bring about the conversion of fructose,specifically or non-specifically, to glucose. The enzymes may also beprepared with the help of other microorganisms, such as fungi, insufficient amounts and the required purities, also by the use of geneticengineering methods which are common today. If it is desired e.g. toproduce the enzymes with other microorganisms, the genetic informationof a microorganism which has been found initially by extensive screeningand which has also been proven as a suitable source of the enzyme withthe desired properties can be transferred to a microorganism which isnormally used for the production of enzymes. Also the modification ofthe enzyme and the production of the enzyme by means of methods whichare presently known or may be developed in the future in the area ofindustrial enzyme development and enzyme production, such as geneticengineering, is possible. The use and the manner of performing all thesemethods for developing and producing the enzyme with the desiredpurities and activities and with the desired properties, in particularwith respect to the stability of the enzyme at various pH values,regarding the optimum of the pH value, the stability at varioustemperatures and temperature optimum, are well known to a person skilledin the art. The explanations in chapter 2 (page 82 to page 130) of thetextbook “Lebensmittel-Biotechnologie and Ernahrung” of Heinz Ruttloff,Jürgen Proll and Andreas Leuchtenberger, published by Springer Verlag1997 (ISBN 3-540-61135-5) describe these methods in detail. Thesemethods are also described in “Advances in Fungal Biotechnology forIndustry, Agriculture, and Medicine” by Jan S. Tkacz, Lene Langeand try,Agriculture, and Medicine” by Jan S. Tkacz, Lene Langeand (published in2004, ISBN 0-306-47866-8). in “Enzymes in Industry: Production andApplications” by Wolfgang Aehle (Editor), published in 2004, ISBN3527295925 and in “Microbial Enzymes and Biotransformations” byJose-Luis Barredo (Humana Press 2005, ISBN 1588292533). These documentsare herewith incorporated into the patent application by reference. Allthis also applies to the enzymes mentioned below that can optionally beadded to the agent according to the present invention.

In this patent application, the activity of glucose isomerase is definedin units, whereby one unit is the amount of glucose isomerase thatconverts 1 g of fructose to glucose in 5 minutes at a pH of 7.5 and atemperature of 37° C. from an initial 10% solution of fructose by weight(i.e. 10 g fructose in 90 g water).

At an enzyme activity determined according to this definition, an agentin accordance with embodiments of the present invention should containglucose isomerase in an amount or activity of 0.01 to 100,000 GIU(=glucose isomerase units), preferably 0.05 to 10,000 GIU andparticularly preferably 0.1 to 1,000 GIU per dose unit.

The wide range of the above mentioned dosages may be explained by thefact that the agent may be used in connection with very different typesof fructose intolerance, namely in hereditary fructose intolerance,intestinal fructose intolerance, and fructose-1,6-diphosphatasedeficiency, in their range of different seventies, and also in milderfructose metabolism disorders. Furthermore, the different dosages alsoresult from the fact that strongly varying amounts of fructose areadministered to the body, depending on the respective food. The enzymeshould be used in a sufficient quantity so that it develops asufficiently high enzyme activity, in other words sufficient glucoseisomerase to convert an amount of fructose consumed in a normal meal(e.g. 10-50 g)—in free or hound form—into glucose.

The agent, in accordance with embodiments of the present invention maycomprise one or more additional enzymes, such as invertase (syn.beta-fructofuranosidase or beta-fructosidase), lactase (syn.beta-galactosidase), maltase (syn. alpha-glucosidase), alpha-amylase,beta-amylase, glucoamylase, pullulanase, isoamylase, amyloglucosidase,cyclomaltodextrin glucantransferase (CGTase). These enzymes have theproperty of releasing fructose and/or glucose from fructose and/orglucose containing substances and foodstuffs—alone or in combinationwith one or more of these enzymes—, whereby the enzymes pullulanase andisoamylase also increase the efficiency of glucoamylase andbeta-amylase. All these enzymes are commercially available (e.g. BioCatInc., Troy, USA or Novozymes A/S, Denmark or Amano Enzymes Inc., Japanor Sigma-Aldrich) and, up to now, have not been used in combination withglucose isomerase in the medical/pharmaceutical field, in particular notin the case of fructose intolerance. Examples for agents in accordancewith embodiments of the present invention include: Glucose isomerase incombination with invertase, or Glucose isomerase in combination withmaltase, or Glucose isomerase in combination with invertase and maltase.

For example, said invertase can release fructose from e.g. sucrose.

By the addition of one or more of these enzymes to the agent, theendogenic release of fructose from fructose- containing substances orfoodstuffs, in particular from sucrose, may also be promoted andaccelerated, so that the conversion of fructose into glucose may occurearlier. Therefore, the addition of one or more of these enzymes to theagent may have the benefit of reducing the required amount of glucoseisomerase.

The activity of invertase is measured in Sumner units (SU, assayavailable e.g. from Bio-Cat Inc., Troy, Va., USA). An SU is defined asthe amount of the enzyme which converts 1 mg of sucrose into glucose andfructose under standard test conditions within 5 minutes at 20° C. and apH value of 4.5. If the agent also contains invertase, the activity ofthe invertase per dose unit should be between 50 and 250,000 SU,preferably between 100 and 150,000 SU and particularly preferablybetween 150 and 100,000 SU per dose unit.

The activity of maltase is defined in units, wherein one unit is theamount of maltase which will convert maltose to D-glucose at a rate ofone milligram per minute at 37° C. and a pH of 4.0 in a 10% maltosesolution by weight.

Where the agent also contains maltase, the activity per dose unit shouldbe between 100 and 100,000 units, preferably between 200 and 50,000units and particularly preferably between 500 and 20,000 units.

In the case of hereditary fructose intolerance, it is particularlypreferable if, in addition to glucose isomerase, folic acid in an amountof 1 mg to 100 mg, preferably 2 mg to 50 mg and particularly preferably3 mg to 10 mg per dose unit are added to the agent(s) according to thepresent invention, as folic acid increases aldolase B activity.

It may also be advantageous to add metal ions to the agent according tothe present invention, especially cations such as Mn²⁺, Mg²⁺, Ca²⁺,Zn²⁺, Fe²⁺, Co²⁺or Cu²⁺, including mixtures thereof, preferably at amolar ratio of 10⁻⁶ to 10⁻². For the (xylose) glucose isomerase fromYamanaka described above, a particularly suitable cation is Mn²⁺.

If the agent is added to a foodstuff before eating or during production,the activity of glucose isomerase should be between 0.01 and 20,000units, preferably between 0.05 and 10,000 units and particularlypreferably between 0.1 and 1,000 units per gram fructose in thefoodstuff.

The capsule sizes mentioned below refer to the sizes defined by CapsugelBelgium BVBA, Bornem, Belgium. The size of capsules should be chosen inaccordance with the specified formulation of the agent.

An agent in capsule form (e.g. of size 3) could contain, e.g., 15 mgglucose isomerase (activity of glucose isomerase 1 GIU/mg) and 135 mgdicalcium phosphate per capsule.

If capsules, e.g. of size 1, are used, they may contain 50 mg glucoseisomerase (activity of glucose isomerase 1 GIU/mg), 5 mg folic acid and150 mg maltodextrin per capsule.

A further example of a composition for the production of capsulesconsists of capsules of size 3 that contain 15 mg glucose isomerase(activity of glucose isomerase 1 GIU/mg), 75 mg 5-D-fructosedehydrogenase (activity of 5-D-fructose dehydrogenase 90 units/mg) and60 mg dicalcium phosphate per capsule.

A further example of a composition for the production of capsulesconsists of capsules of size 00 that contain 300 mg glucose isomerase(activity of glucose isomerase 1 GIU/mg) and 170 mg dicalcium phosphateper capsule.

A unit dosage form in accordance with embodiments of the invention mayfor example contain between 0.01 and 100,000 GIU (=glucose isomeraseunits) and between 1 mg and 100 mg folic acid per dose unit. Inaddition, suitable additives in the required amount may be used.

An agent in accordance with embodiments of the invention can be madeavailable for medical purposes and non-medical purposes, e.g. as apharmaceutical composition, medical device, foodstuff, foodstuff forparticular nutritional uses, food for special medical purposes, medicalfood, food supplement, dietary supplement, dietetic food supplement,health food, nutraceutical, or food additive.

In accordance with embodiment of the invention, an agent can be used toconsiderably alleviate or eliminate the symptoms and health impairmentscaused by fructose intolerance. The invention presented here is suitablefor use in the case of fructose intolerance and for the therapeutictreatment of fructose intolerance.

The invention claimed is:
 1. A method of conversion of fructose intoglucose in a human subject who would benefit from such conversion, whichmethod comprises the oral administration to the subject of a glucoseisomerase in an amount effective to convert fructose into glucose in thedigestive tract of the subject.
 2. The method according to claim 1wherein the amount of glucose isomerase is an amount effective toconvert 10-50 g of fructose into glucose.
 3. The method of claim 1,wherein the administration occurs after the intake by said subject offructose or a substance or foodstuff containing fructose in pure form orfrom which fructose can be released in the digestive tract.
 4. Themethod of claim 1, wherein said glucose isomerase is contained in apharmaceutical composition.
 5. The method of claim 1, wherein saidglucose isomerase is contained in a foodstuff.
 6. The method of claim 5,wherein the foodstuff is selected from the group consisting of (a)foodstuffs for particular nutritional uses; (b) foods for specialmedical purposes; (c) medical foods; (d) food supplements; (e) dietarysupplements; (f) dietetic food supplements; (g) health foods; (h)nutraceuticals; and (i) food additives.
 7. The method of claim 6,wherein the foodstuff is a dietary supplement.
 8. The method of claim 1,wherein the glucose isomerase is administered prior to said subject'seating, concurrently with said subject's eating or after said subject'seating.
 9. The method of claim 1, wherein the glucose isomerase isformulated in a form selected from the group consisting of (a) coated ornon-coated capsules (b) coated or non-coated tablets (c) capsulescontaining coated or non-coated pellets, granules, or micro- ormini-tablets (d) tablets pressed from coated or non-coated pellets,dragees, or micro- or mini-tablets (e) gel caps (f) a solution, (g)drops, (h) a suspension (i) a gel and (j) a powder.
 10. The method ofclaim 9, wherein the coating of the capsules, tablets, pellets,granules, micro- or mini-tablets and dragees is selected from the groupconsisting of cellulose acetate phthalate, cellulose derivatives,shellac, polyvinylpyrrolidone derivatives, acrylic acid, polyacrylicacid derivatives and polymethyl methacrylate.
 11. The method of claim 1,wherein said glucose isomerase is administered with at least one metalion.
 12. The method of claim 1, wherein the glucose isomerase is axylose isomerase.
 13. The method of claim 1, wherein said glucoseisomerase is administered with a second enzyme which cleaves fructosefrom a sugar which is more complex than fructose.
 14. The method ofclaim 13, wherein said second enzyme is selected is from the groupconsisting of invertase, malatse and combinations thereof.